Do girls like guys in 5th grade?

My friend Brendan and i both like the same girl. Brendan had the nerve to ask her out, but she now hates him. I have been working up to nerve to ask her out, but don't know if i should. i don't know why she hates him. I think it is because he asked her a very NAUGHTY question (if you know what i mean). It might be that she doesn't like guys in general. but the weird part is, she says this to every boy "guess what? I HATE U!"(she never says it to me though). is it safe to ask her out, if not how how long do i wait?